Jason Ritter Jason Ritter

Despite a less than eventful fall launch, Jason Ritter is remaining "cautiously optimistic" that The Event will return for a second season. But first, he preps us for tonight's two-hour mid-season return. Last we saw Ritter's character, Sean, he had rescued girlfriend Leila (Sarah Roemer) from a kidnapping connected to what he describes as "the biggest U.S. cover-up of all time. We figured out the government has been holding a group of alien detainees in Alaska who have not seemed to age for the past 66 years."

Together, the duo also discovered that Leila's father, Michael (Scott Patterson), was actually one of several aliens who've been living in society as "sleepers." But that's not the only twist. "There is also a billionaire who has been performing all these experiments on little girls — including Leila's little sister, Samantha [Anna Clark] — that seems to age them rapidly," says Ritter. "He can also take the serum so that it makes him look young."

In the remaining episodes, all the stories will converge. And for the first time in his career, Ritter will have to downplay his million-dollar smile. "The stress is starting to take a toll on Sean and some of the innocent qualities he had at the beginning of the show are slowly being stripped away," he says. "He is having to become hardened to survive." In other words, adds Ritter, "No more Mr. Nice Guy!"

The Event airs Monday at 8/7c on NBC.

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